This invention relates generally to hollow link jewelry chain, and more particularly to hollow links having unique cross-sectional shapes not seen before in the art.
Jewelry chains, and in particular jewelry rope chains, are conventionally formed from solid or hollow annular links having cross-sections that are also annular in configuration. Such links are also conventionally toroidal in configuration, which when combined with an annular cross-sectional configuration results in a link having the shape of a doughnut.
Chain links having non-annular cross-sectional configurations are also known, as shown for example in U.S. Pat. No. 5,537,812 to Rozenwasser. The Rosenwasser ""812 links have a cross-section defined by a hollow base portion of generally uniform wall thickness and at least one reinforcing rib portion joined on the base portion and protruding beyond the base portion about the entire circumference of the link. A high luster surface may be achieved by removing the rib portion along certain selected portions of the ""812 links, particularly during the faceting operation. Non-traditional cross-sections are also discussed in U.S. Pat. No. 5,285,625 to Ofrat et al. The Ofrat et al. reference, however, focuses on non-standard cross-sections of solid links and hollow links having an annular cross-sectional configuration.
In a continuing effort to reduce the material costs involved in manufacturing jewelry chains while still maintaining an aesthetically pleasing appearance, the present inventor has recognized that a hollow link having an annular configuration has a certain material cross-sectional area defined by B(r22-r12), where r2-r1 designates the thickness of the sheet of material used to form the link. Normally, hollow links are provided with seams through which a metal former may be dissolved, with the metal former being used to prevent deformation of the link sidewalls during the link creation process. When the seam is rather minimal, as is the case with most prior art chain links, the cross-sectional surface area will approach that of a seamless, annular cross-section hollow link, or B(r22-r12). When the seam is rather substantial, the cross-sectional surface area will be defined as B(r22-r12) minus the seam. The larger the size of the seam, the greater the rate at which the metal former dissolves therethrough.
Taking the above-referenced hollow link having an annular cross-section and a certain sheet thickness, any link having the same sheet thickness and a non-annular cross-section about which the annular cross-section of such annular link could be circumscribed would require less material than the link having an annular cross-section. In other words, if an annular cross-sectional configuration can be circumscribed about a non-annular cross-sectional configuration, with both cross-sectional configurations having the same sheet thickness, the non-annular cross-sectional configuration will inherently use less material than the annular cross-sectional configuration. Likewise, for any straight line, a circular arc connecting those same two end points would have a greater length and for a uniform thickness, a greater area.
Significant advances in the jewelry chain art are defined by the look of the resultant product and the method of making the same. Hollow-link chains advanced the art over solid-link chains by producing a chain with a similar appearance at a fraction of the cost. Consequently, great attention has been paid to the method of manufacturing and forming the links that are intertwined into jewelry chains, with improvements or enhancements in each link resulting in a chain that is, on the whole, improved or enhanced over the prior art.
In an effort to produce a chain that is an improvement over the prior art, the present inventor has devised a way to produce a chain with a reduction in the amount of material used to form the links. The present inventor accomplishes such task by forming links from a wire or a sheet of material having a uniform thickness throughout, and with the resultant link having a non-annular cross section. Such cross-section of the link will also preferably be symmetric about a vertical, centerline plane or axis and, preferably on each side of the centerline plane, have at least two sides that meet at a point of inflection, or the location characterized by the change of direction from the first side to the second side. In some embodiments, each half of the centerline plane will have at least one side converging toward the centerline plane. Such configurations further reduce the extent of the cross-section material of the link with respect to prior art annular, cross-sectional counterpart.
It is an object of the present invention, therefore, to provide a jewelry chain formed from links with a non-annular cross-section throughout.
It is a further object of the present invention to provide a jewelry chain formed from links with a non-annular cross-section of uniform thickness.
It is a still further object of the present invention to provide a jewelry chain formed from links with a non-annular cross-section that is symmetric along a centerline plane.
It is a still further object of the present invention to provide a jewelry chain formed from links with a non-annular cross-section, that is symmetric along a centerline plane and on each side of the centerline plane there are at least two side walls that meet at an inflection point.
It is a still further object of the present invention to provide a jewelry chain formed from links with a non-annular cross-section, that is symmetric along a centerline plane and on each side of the centerline plane there is at least one side that converges toward such centerline plane.
It is a still another object of the present invention to provide a jewelry chain formed from links with a non-annular cross-section, where such chain is formed from less precious metal than if the links were annular in cross-section.
Still other objects and advantages of the invention will become clear upon review of the following detailed description in conjunction with the appended drawings.
A chain link of hollow construction and substantially uniform thickness throughout, for intertwining with other chain links to form a jewelry chain, has a non-annular cross-section that is symmetric along a centerline plane through said cross-section. The cross-sectional shape of the link preferably has on each side of the centerline plane, at least two side walls that meet at an inflection point. On each side of the centerline plane, at least one side preferably converges toward said centerline plane. The link of the invention is constructed from less material than a similar counterpart hollow link having an annular cross-section, without sacrificing the aesthetic appeal of such link. Thus, a chain formed from the non-annular-cross-sectional links of the invention will use less material than if such chain were formed from links having an annular cross-section, which results in a reduction in manufacturing cost and an equivalent reduction in the cost to the consumer.